Last updated: May 3, 2025
In Knoxville, Tennessee, understanding the UV Index is crucial for protecting your skin from the sun’s harmful rays. With peak UV levels reaching up to 11 during midday hours, being aware of these metrics can help you prevent sunburn and promote long-term skin health. Knoxville's Cfa climate offers plenty of sunny days, making it essential to stay informed about UV exposure risks. By checking the UV Index regularly, you can ensure you're taking the necessary precautions to enjoy the outdoors safely, no matter the season.
The UV Index throughout the day presents a clear trajectory of increasing intensity, peaking dramatically as the sun reaches its zenith. At 07:00, the index starts modestly at 1, signifying minimal risk. However, as the hours roll on, from 08:00 to 10:00, it climbs steadily to 6, marking the onset of moderate exposure. The real surge occurs between 11:00 and 13:00, where the index hits a staggering 11, indicating a very high risk for unprotected skin. Even as it begins to taper off in the afternoon—returning to 9 by 15:00 and further down to 4 by 17:00—the day's UV intensity serves as a reminder of the importance of sun protection. By 19:00, it drops back to a safe 1, allowing for a sigh of relief as daylight wanes. Embrace the sun wisely!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 6 | high | 25 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 11 | extreme | 10 min |
| 15:00 | 9 | very high | 15 min |
| 16:00 | 6 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index experiences significant seasonal fluctuations, with the highest levels occurring during the summer months. Notably, from May to August, the UV Index reaches extreme levels of 11, indicating a high risk for skin damage with a burn time of only 10 minutes. In contrast, the winter months, especially January and December, see moderate UV levels of 4, allowing for a safer exposure time of 30 minutes. The months of February and March also present heightened risks with UV indices of 6 and 8, respectively, highlighting the necessity for caution as spring approaches. Residents and visitors are advised to protect their skin during April to September when the UV values are particularly elevated. Measures such as wearing sunscreen, protective clothing, and seeking shade during peak sun hours are strongly recommended to reduce the risk of sunburn and long-term skin damage.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chicago UVI | 3 | 4 | 6 | 8 | 9 | 10 | 10 | 9 | 8 | 6 | 4 | 2 |
| Brooklyn UVI | 3 | 5 | 6 | 8 | 10 | 10 | 9 | 9 | 8 | 6 | 4 | 2 |
| New York City UVI | 3 | 5 | 6 | 8 | 10 | 10 | 9 | 9 | 8 | 6 | 4 | 2 |
| Los Angeles UVI | 4 | 6 | 8 | 9 | 10 | 11 | 11 | 10 | 10 | 7 | 5 | 4 |
| Knoxville | 4 | 6 | 8 | 10 | 11 | 11 | 11 | 10 | 9 | 7 | 5 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |